To complete this level you need to use the virus blocks to fill the two spaces under the line blaster encased in glass. Then it can drop and break, releasing the blaster to remove the metal blocks
Do not be tempted to match the virus blocks first
What you need to do first is clear the block diagonally to the virus blocks, of mesh
Work your way in with matches until this block is clear so that the virus will spread to it
Then, remove the two under the line blaster
Next, clear the blocks so another virus block can fall, then make a match elsewhere while the virus spreads to beside the other
It will help greatly if you can also clear the board of all the other virus blocks (because one spreads every move and you'll only want the ones in the bottom left corner to spread)
It will also help if you can keep the mesh on the blocks that surround the virus blocks to stop it spreading to them instead of where you need it to go